The present invention relates to an electrophotographic copying machine and, more particularly, to a mechanism for driving an original carrier or an optical exposure system in the electrophotographic copying machine.
In the conventional electrophotographic copying machine having a travelling original carrier or a travelling optical exposure system, an electromagnetic clutch or a spring clutch is used to transmit the rotation of a motor to the travelling original carrier or the optical exposure system for driving them to reciprocate. In this case, two clutch mechanisms are required, one for driving the original carrier or the exposure system forward (referred to as a feedforward clutch hereinafter) and the other for driving the original carrier or the exposure system backward (referred to as a reverse clutch hereinafter). The control of these clutches and controls or actuation of a charging system and an exposure lamp are achieved by an electric circuit including relay assemblies.
When the electromagnetic clutch is employed for driving the original carrier or the exposure system, the system is compact in size, but the system becomes expensive. When the spring clutch is employed, a solenoid is required to control the operation of the spring clutch. In the conventional system, solenoids are required for the respective spring clutches, and relay assemblies are required for the respective solenoids. Therefore, a large number of elements are employed in the system. This makes the mechanism complicated and expensive.
Accordingly, an object of the present invention is to provide an improved mechanism for reciprocating an original carrier or an optical exposure system in an electrophotographic copying machine.
Another object of the present invention is to provide a mechanism for driving an original carrier or an optical exposure system in a reciprocating fashion, which includes spring clutches and only one solenoid.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a control clutch is provided in addition to a feedforward clutch and a reverse clutch. These clutch mechanisms are driven to rotate in given directions when the electrophotographic copying machine is enabled. A cam mechanism and latch mechanisms are associated with the control clutch. A combination of the cam mechanism and the latch mechanisms controlled by a solenoid selectively operates the feedforward clutch and the reverse clutch, thereby driving an original carrier or an optical exposure system to reciprocate.